As a method of identifying the location of a terminal, there is a method disclosed in Patent Literature 1 or Patent Literature 2.
The method disclosed in Patent Literature 1 is a method of acquiring location information from a terminal situated at a short distance and identifying the self-location based on the acquired location information.
In this method, the terminal is required to be present at a short distance. Moreover, as the distance between terminals is larger, errors in location become larger.
The method disclosed in Patent Literature 2 is a method of identifying the distance between terminals based on the intensity of radio waves or the delay of radio waves, geometrically deriving a directional relationship between the terminals based on the identified distance, and identifying the locations of the terminals based on the derived directional relationship.
In this method, terminals which are able to be accessed by all of the terminals whose locations are identified are required. Specifically, in the case of identifying the location of each of a terminal A and a terminal B, a terminal C, a terminal D, and a terminal E which are able to be accessed by both the terminal A and the terminal B are required. In this case, if at least one of the terminals C to E is absent, it is impossible to identify the location of each of the terminal A and the terminal B.